A vehicle typically includes a climate control system which maintains a temperature within a passenger compartment of the vehicle at a comfortable level by providing heating, cooling, and ventilation. Comfort is maintained in the passenger compartment by an integrated mechanism referred to in the art as a heating, ventilation and air conditioning (HVAC) air-handling system. The air-handling system conditions air flowing therethrough and distributes the conditioned air throughout the passenger compartment.
The air-handling system commonly employs a plurality of doors within a housing to control a flow of air therethrough. For example, the air-handling system may include a temperature door for controlling a flow of air through heat exchangers that may be disposed within the housing. In some cases, the temperature door may be adjusted between a first position configured to direct an entirety of the flow of air through a heater core to add thermal energy to the flow of air, and a second position configured to direct the entirety of the flow of air through an evaporator core to remove thermal energy from the flow of air. The temperature door may further be adjusted to an intermediate position to direct a first portion of the flow of air to the heater core and a second portion of the flow of air to the evaporator core. In other cases, the evaporator core may be disposed upstream of the temperature door to cause the entirety of the flow of air to flow through the evaporator core before encountering the temperature door. In such cases, the temperature door may be adjusted between a first position configured to direct the entirety of the flow of air through the heater core and a second position configured to bypass the entirety of the flow of air through a bypass passageway, wherein the flow of the air is not subjected to additional heating by the heater core. The temperature door may further be adjusted to an intermediate position to direct a first portion of the flow of air through the heater core and a second portion of the flow of air through the bypass passageway bypassing the heater core.
The air-handling system may also include a mode door configured to control a distribution of the flow of air to the passenger compartment of the vehicle. For example, in a first position, or upper mode, the flow of air may be directed to an upper conduit and provided to a vent directed towards a windshield or a passenger within the passenger compartment. In a second position, or lower mode, the flow of air may be directed to a lower conduit and provided to a vent directed towards a floor area of the passenger compartment. Additionally, the mode door may be positioned intermediate the first position and the second position, in a mixed mode, to provide a first portion of the flow of air to the upper conduit and a second portion of the flow of air to the lower conduit.
To allow the temperature of the flow of air to be fully adjusted between a cold temperature and a hot temperature for each of the upper mode, the lower mode, and the mixed mode, each of the temperature door and the mode door must be rotated independently of each other. Typically, independent rotation of the temperature door and the mode door requires each of the temperature door and the mode door to be controlled by distinct actuators, wherein a first actuator controls the temperature door and a second actuator controls the mode door. The use of two actuators is costly, requires additional manufacturing and assembly, and necessitates independent controls for each of the actuators.
Accordingly, there exists a need in the art to efficiently and simultaneously control a temperature door and a mode door of an air-handling system in a low cost manner.